Wednesday morning at 6 a.m., a security guard at the smashed Hotel Montana woke up search and rescue chief Fred Golba, from Palm Bay. The guard said he was hearing tapping in the rubble, eight days after the earthquake and four days after the last live person had been rescued. At this luxury hotel perched in the wealthy hill district of Petionville, rescue teams from half a dozen countries have swarmed over this mound of rubble for a week desperately trying to free the international clientele that packs the hotel year-round.

Twelve people were rescued alive between Jan. 13 and Saturday, but 25 are still missing. Thirteen of them are from the United States, some of them students and faculty from Lynn University in Boca Raton. It has been four days since the last person was pulled out alive.

So the tapping heard early Wednesday gave a needed boost to the weary rescue teams.

"When the guard showed me where he heard tapping this morning, I got excited because it was where we had heard tapping on Monday," Golba said.

But before he could alert his U.S. team, the ground began shaking violently as a 5.9 magnitude aftershock rattled the capital. Searchers scrambled from their tents and ran.

Two hours later, a Chilean team of rescuers in red jumpsuits rappelled 40 feet up to the top of the concrete slab that once was the roof of the multi-story hotel. Their Labrador Berkan climbed in the opening within 12 feet of the earlier tapping and began barking wildly.

"This was a very good sign," said Augusto Salvo, from the Chilean team.

But the earthquake at dawn Wednesday had shifted and narrowed the path into the rubble, setting the search back.

"We are continuing to dig and trying not to be discouraged, but we are not hearing anything now," said Minsung Kim, a Korean team member.

Across the ruined city, the last few days have yielded surprising tales of improbable survival. Ena Zizi, 69, was rescued from the Roman Catholic compound on Tuesday. And overnight Tuesday, Lozama Hotteline, 26, was pulled from a supermarket in midtown Port-au-Prince, smiling and singing hymns.

The chance to add to the list of miracles spurred the rescue crews through Wednesday.

Indeed, one rescue was reported. The International Medical Corps (IMC) said it cared for a child found in quake ruins on Wednesday. The boy's uncle told doctors and a nurse with the Los Angeles-based organization that relatives pulled the 5-year-old from the wreckage of his home after searching for a week, said Margaret Aguirre, an IMC spokeswoman in Haiti.

Family members working to recover a body said they heard a voice saying, "I'm here, I'm here," Aguirre recounted.

The boy was dehydrated, drinking four bottles of water and two juices, but otherwise unharmed, she said.

But hopes were dimming, as the crews reckoned with the inevitable moment when their work would shift from rescue, and its promise of an occasional miracle, to the grimmer task of recovering bodies.

"It's like trying to find a needle in a haystack, and each day the needles are disappearing," Steven Chin of the Los Angeles County rescue team told the Associated Press.

At the Montana, the searchers used jackhammers to crush the concrete into pebble-sized pieces which they shoveled out.

Hotel rooms in the garden lanai area, which is still intact, have been converted to a morgue — bodies in gray bags lie on the white marble floors near French doors that look out on birds of paradise and bougainvillea that smell like rotting flesh.

By noon Wednesday, the Korean team of 25 had taken over the search. After digging a foot deeper in three hours, they took Mani, their German shepherd to the opening.

The dog crawled in and was silent.

No life.

"We are hoping today is not the turning point for finding anyone alive," said Salvo.

Golba doesn't want to believe that's true: "People have been found alive in similar situations after two weeks," he said. "I'm gong to keep looking and hoping until then."

And, after Tuesday?

"I don't want to think about that now," he said. "Tomorrow we'll be back here working."